Debugger: Make pinned tooltips a frameless Tool window

This avoids the "StayOnTop" situation described in QTCREATORBUG-13397
for the case of pinned tooltips.

Task-number: QTCREATORBUG-13397
Change-Id: I3801368c07895b652e10fe1d173b21cef7869ed0
Reviewed-by: hjk <hjk121@nokiamail.com>

src/plugins/debugger/debuggertooltipmanager.cpp

@@ -688,7 +688,7 @@ public:
         if (parentWidget()) {
             // We are currently within a text editor tooltip:
             // Rip out of parent widget and re-show as a tooltip
-            Utils::WidgetContent::pinToolTip(this);
+            Utils::WidgetContent::pinToolTip(this, ICore::mainWindow());
         } else {
             // We have just be restored from session data.
             setWindowFlags(Qt::ToolTip);